|Budget Amount *help
¥3,000,000 (Direct Cost : ¥3,000,000)
Fiscal Year 1999 : ¥1,400,000 (Direct Cost : ¥1,400,000)
Fiscal Year 1998 : ¥1,600,000 (Direct Cost : ¥1,600,000)
To understanding the relationship between phenotypic modulation of vascular smooth muscle cells (SMC), and matrix remodeling process, in vitro culture model for the phenotypic modulation of SMC was established. The culture conditions were verified by the alteration of serum-concentration and final cell densities. The expressions of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) were determined with Western blotting and enzyme immunoassays. Collogenolytic activity and gelationolytic activity were also measured. The Expressions and activities of MMP-1, TIMP-1-3, and MMP-1rrIMP-1 expressions were maximal in the cells displaying the proliferative phenotype. MMP-2 expression was not changed with SMC phenotypes. The adenovirus vector expressing TIMP-1 was prepared and the analysis for SMC phenotypes or functions using this vector is addressing.
The amount of extra-cellular matrix also regulates SMC phenotypes via the function of cell-cycle regulatory genes. The expression patte
rn of p2lWaf-1, cyclin-dependent kinase inhibitor was observed in either cultured SMC or human atherosclrotic lesions. p2lWaf-1 expression was enhanced in the proliferating cells in accordance with G0-G1 transition. In vivo, the expression was dominantly detected in neo-intimal atherosclerotic lesions. p21Waf-1 may contribute not only in cell-cycle arrest, but also in an appropriate cell cycle progression. Adenovirus vector expressing p21Waf-1 induced cell cycle arrest and hypertrophy in SMC, but not promoted re-differentiation and apoptosis.
In conclusion, Matrix-degradation is an important function of SMC, which is coordinately regulated with SMC phenotypes. These SMC functions may be mediated by both endogenous and exogenous growth factor signalings. Proliferation is considered to be tightly regulated by cell-cycle regulatory proteins, such as p21Waf-1, of which function may modulate SMC phenotypes. These finding may contribute to understanding the biology of vascular smooth muscle cells. The adenovirus-mediated gene transfer method used in this project, may imply clinical alteration of human atherosclerosis in the therapeutic implications. Less